26 Apr
2018
26 Apr
'18
8:23 p.m.
Eric Smith via cctalk wrote:
On Thu, Apr 26, 2018, 15:59 Bill Gunshannon via cctalk
<
cctalk at classiccmp.org> wrote:
Interesting. HP made ISA card versions of early (or actually, pre-)
HP9000-300 that were designated as "Basic Language Processors", hosting
a 68000 and having GPIB I/O. Interesting beasts. I believe that they
were able to take control of the ISA bus for at least some functions;
they were fast for their time, and it was easy to share GPIB-acquired
data with the MSDOS world.
I believe the Z-80 was subordinate to the M68K.
In high-level conceptual term, maybe, depending on the software.
In term of the actual capabilities of the hardware, the Z80 was firmly in
control of _everything_ in the machine, including control over the MC68000,
while the MC68000 had no direct control over anything but its MMU (built
from TTL) and memory. If code running on the MC68000 wants to talk to
anything at all, disk, tape, console, printer, serial ports, etc., all it
can do is politely request that of the Z80. In that sense it's like the CPU
of a CDC 6600, which can't do anything without the PPUs